1. Technical Field
The present invention relates to a polling system and a polling method using the same.
2. Description of the Related Art
Presently, an inertial sensor has been used in various applications, for example, the military such as an artificial satellite, a missile, an unmanned aircraft, and the like, vehicles such as an air bag, electronic stability control (ESC), a black box for a vehicle, and the like, hand shaking prevention of a camcorder, motion sensing of a mobile phone or a game machine, navigation, and the like.
The inertial sensor has generally adopted a configuration in which a mass body is adhered to an elastic substrate such as a membrane, and the like, in order to measure acceleration and angular velocity. Through the above-mentioned configuration, the inertial sensor may calculate the acceleration by measuring an inertial force applied to the mass body and the angular velocity by measuring a Coriolis force applied to the mass body.
In detail, a method of measuring the acceleration and the angular velocity using the inertial sensor will be described below. First, the acceleration may be calculated by Newton's law of motion “F=ma”, where “F” represents the inertial force applied to the mass body, “m” represents a mass of the mass body, and “a” is the acceleration to be measured. Among others, the acceleration a may be obtained by detecting the inertial force F applied to the mass body and dividing the sensed inertial force F by the mass m of the mass body that is a predetermined value. Further, the angular velocity may be obtained by the Coriolis force “F=2mΩ×v”, where “F” represents the Coriolis force applied to the mass body, “m” represents the mass of the mass body, “Ω” represents the angular velocity to be measured, and “v” represents the motion velocity of the mass body. Among others, since the motion velocity V of the mass body and the mass m of the mass body are values known in advance, the angular velocity Ω may be obtained by detecting the Coriolis force (F) applied to the mass body.
Meanwhile, a piezo-electric element in the inertial sensor according to the prior art including the following prior art document is deformed when applied with voltage, but generates charges when applied with an external force. With above the characteristics, the piezo-electric element may be variously used in various actuators, sensors, and the like. In addition, as the piezo-electric element, there are various materials, such as Aln, ZnO, quartz, and the like, but a PZT having a piezo-electric constant has been mainly used in various fields.
Further, in order to improve the characteristics of the piezo-electric element, the piezo-electric element needs to be subjected to a polling process before most elements are manufactured and then operated. Herein, the polling process is to improve piezoelectric characteristics by applying temperature and voltage.
However, in connection with the polling process, when the plurality of elements is individually subjected to the polling process, productivity may be degraded and when the plurality of elements is subjected to the polling process at one time, accurate and effective polling may not be implemented due to defective elements.